176 PRINCIPLES OF ANIMAL NUTRITION. 
to fat production, and of the very large differences between this 
amount and the fat computed to have been actually formed, the 
possible errors of the method are relatively insignificant, and these 
investigations, together with the earlier ones, must be regarded as 
establishing the fact of a formation of fat from carbohydrates. 
The earliest experiment to be published in full demonstrating 
the production of fat from carbohydrates in the body of the dog, 
was by Munk.* The animal was deprived of food long enough to 
render it certain that but traces of fat remained in the body. It 
was then fed for twenty-four days on a diet consisting of small 
amounts of meat, with some gelatine, and large quantities of 
starch and sugar. In the body of the animal at the close of the 
experiment 1070 grams of fat were found, of which Munk estimates 
that at least 960 grams must have been produced during the experi- 
ment, while the proteids fed could have produced as a maximum 
only 415.3 granis and the meat itself contained but 75 grams of fat. 
Even if a formation of fat from gelatine be admitted, a considerable 
excess of fat remains unaccounted for except by the carbohydrates 
of the food. 
Respiration Experiments.—There are not wanting, however, for 
final demonstration, experiments with the respiration apparatus, in 
which the total income and outgo of nitrogen and carbon has heen 
determined. 
Meissl, Strohmer, & Lorenz,t in very carefully conducted respi- 
ration experiments upon swine, using a wide, a medium, and a 
narrow nutritive ratio, obtained the following results: 
Food, Proteid | Equivalent| Fat of Pas Fat 
Grms. peau ae goes aud Provelila Peauneh: 
7 . : Grms. Grms. 
Ric@ reco geese eek eS 65.4 33.6 7.9 41.5 353.9 
AE aia crarnters Mascs tee shoes 64.1 33.0 16.4 49.4 413.2 
Barley’. as deip ose ee ae 88.0 45 .2 15.2 60.4 208.7 
Flesh meal, rice, and 
whey.............. 381.6 196.1 48.6 244.7 256.3 
Almost simultaneously C. Voit { gave a preliminary account of 
* Virchow’s Archiv, 101, 91. 
+ Zeit. f. Biol., 22, 63. 
$Sitzungsber bayr. Acad d. Wiss.; Math. Phys. Classe, 1885, p. 288. 
